Conventional piston-based compressors use mechanical seals to resist leakage at the expense of additional mechanical friction. This type of compressor requires the design of dynamic seals that are typically a significant source of inefficiency, both volumetrically and mechanically, while the piston applies the work to the fluid in a compression chamber.
One existing advancement that has some limited applications is the use of roll-sock seals in air compressors. These designs use a compliant diaphragm material to improve efficiency of the mechanical piston seal by replacing the sliding seal with a rolling contact of the diaphragm on the piston chamber or piston while the piston continues to do the work on the fluid in the compression chamber. Such compressors use roll sock seals to eliminate fluid flow through small gaps internal to the compressor and are not mechanically designed to survive the large forces experienced when exposed to larger areas. As a result, this type of roll sock seal does not reduce the mechanical burden of internal loading and high tolerances that are typical of even standard compressors.
Roll socks are generally constructed from elastomers, and elastomers with fiber reinforcement (ideally but not always axial). The roll sock tube must be sufficiently compliant to fit both the inside cylinder diameter and the outside piston diameter, between which two diameters it rolls. It must also be sufficiently thin and compliant to continuously bend in a full semicircle between the two, without compromising fatigue life and while resisting a useful pressure. These geometrically imposed longevity and environment constraints limit the utility of roll sock seals to relatively specialist applications.
Additionally, diaphragm compressors are known in the art. However, the displacement of such diaphragm compressors is generally small for higher strength lower elastic range more rigid diaphragm materials. Mechanically driven diaphragm pumps can use elastomer diaphragms, at low pressures, and higher strength materials, including steels, at higher pressures. Diaphragm pumps tend to have low power-to-weight ratios due to use of low strength elastic diaphragm materials or low displacement high strength diaphragm materials that operate in bending instead of in tension, as per an ideal thin wall pressure vessel.
Due to the low deflection capability of high strength semi rigid materials that are conventionally used in such systems, diaphragm pumps also tend to have large diameters and short strokes, not only departing substantially from the form of an ideal pressure vessel, but also having low volume, which results in low power. Diaphragms that use highly elastic materials so as to achieve greater strokes and volumes generally do so by using low-strength materials, which reduce power-to-weight ratio, operating pressure, and can reduce longevity or cycle life of such diaphragms.
In view of the foregoing, a need exists for an improved compressor system and method in an effort to overcome the aforementioned obstacles and deficiencies of conventional compressor systems.
It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure.